Problems with mono.exe, can't load ANY scripts

Here’s a copy of my bug report, maybe someone already had the same problem:


  1. What happened

I’m completely new to Unity and installed it yesterday for the first time…

Whenever I open a project that contains scripts, I get an error message on startup saying that “mono.exe doesn’t work anymore”. I get this message twice, at the same time. Then Unity launches and I get an internal compiler error, but there doesn’t seem to be any detailed error description, neither in the console nor in the editor log. I can open and edit scripts in MonoDevelop without problems.

It happens even when I create a new project and select the prefab scripts that come with Unity free to be installed. And it happens with sample projects from the Unity website as well.

When I create a new “blank” project without selecting anything in the “new project” dialogue, I don’t get any errors, but as soon as I add a script to the assets or to an object, I get the “mono.exe” error and the internal compiler error again. It happens with both C# and JavaScript files.

Here’s what I already tried so far, without success:

  • Change mono develop in preferences/external tools manually from built-in to the app file in the programs(x86)\Unity\MonoDevelop folder
  • Change the external tool to notepad
  • Unistall Unity, manually erase the MonoDevelop folder, reinstall
  • Disable Antivirus + Firewall
  • Install + run as administrator
  1. How can we reproduce it using the example you attached

Not sure about that, as it seems to be a general problem with mono and my system.


Here’s the logfile: unity error log - Pastebin.com
and the system info: unity system info - Pastebin.com

I’m having the same problem, unable to compile my scripts as it cannot find mono.exe.
I have looked at the directory structure and there is no, ‘mono.exe’ just a ‘mono file’.

This is a new download version 4.6.1, this did not happen in previous version.

Please help… somebody…somewhere…out there…in the gaming universe!
Cheers :slight_smile:

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